[exim-dev] patch for eximstats

Hi All

I have view as in the merge it comes made the sum of the values while to
me it interests an average on the histogram.
I have made one small modification on the eximstats in order to create
histogram with the average of the values.
In truth on a merge of report the value divides for 7.
I have added the option "-hw" that it works alone if used together to
the option "-merge".
I would suggest the implementation an option like mine "-hw", an option
"-av" that it creates an average that depends of the number of report
merged.

Andrea